Parnell spent his entire ten-year career with the Boston Red Sox, compiling a 123–75 record with 732 strikeouts, a 3.50 earned run average, 113 complete games, 20 shutouts, and innings pitched in 289 games. He has the third-highest career winning percentage for a left-hander in Fenway Park, at 71–30. Parnell was a better than average hitting pitcher, posting a.198 batting average with 52 runs, 1 home run, 50 RBI and 29 bases on balls. Defensively, he was better than average, recording a.971 fielding percentage which was 13 points higher than the league average at his position. Parnell enjoyed his best season in 1949 when he went 25–7, leading the league in wins, ERA, complete games and innings. He was the starting pitcher for the American League in that year's All-Star Game and was selected again in 1951. After two 18-win seasons in 1950 and 1951, and a 12–12 record in 1952, Parnell went 21–8 in 1953 with a 3.06 ERA and a career-high 136 strikeouts. On July 14, 1956, he no-hit the Chicago White Sox, 4–0, at Fenway Park. The no-hitter was the first for a Red Sox pitcher since Howard Ehmke in 1923, though this would prove the final highlight of Parnell's career, which would come to a premature end after the 1956 season, due to a torn muscle in his pitching arm. It would take 52 years until another Red Sox lefty would throw a no-hitter, a feat accomplished by Jon Lester in 2008. Parnell still holds the Red Sox career mark for left-handed pitchers in games started, innings and victories. Parnell once said the southpaw's enemy at Fenway Park was the smallness of the foul territory, not the wall. It's been said that following a victory in Fenway Park during which Johnny Pesky hit the deciding home run near the right field foul pole, Parnell named it the "Pesky Pole" or Pesky's Pole. Research, however, shows that Pesky hit just one home run in a game pitched by Parnell, a two-run shot in the first inning of a game against Detroit played on June 11, 1950. The game was eventually won by the visiting Tigers in the 14th inning on a three-run shot by Tigers right fielder Vic Wertz, as Parnell earned a no-decision that day.
Post-playing career
After his playing career, Parnell managed the New Orleans Pelicans of the Class AASouthern Association in 1959 and a series of Red Sox farm clubs from 1961 to 1963. Parnell was a member of Boston's radio and television announcing crew from 1965 to 1968 and the Chicago White Sox' TV crew in 1969. He called the last out of the final regular season game of the 1967 Red Sox "Impossible Dream" season on WHDH-TV:
"Little soft pop-up...Petrocelli will take it...he does! The ball game is over! The Red Sox win it! And what a mob on this field! They're coming out of the stands from all over!"
